Steam infuser



M. E. ENGEL STEAM INFUSER Filed Oct.

June 17, 1969 TOR MARTzN '"YE'NGEL BY fn'f ATTORNEYS United StatesPatent O 3,450,022 STEAM INFUSER Martin E. Engel, Park Ridge, Ill.,assignor to National Dairy Products Corporation, New York, N.Y., acorporation of Delaware Filed Oct. 5, 1965, Ser. No. 493,162 Int. Cl.B65b 55/06; A23c 3/00; Blf 15/06 U.S. Cl. 99-251 3 Claims ABSTRACT OFTHE DISCLOSURE Apparatus for infusing steam into a liquid to be heatedhaving a cylindrical chamber to which are fixed tangential liquid andsteam injecting pipes. The mixture is directed out of the top of thecylindrical chamber and through a zigzag conductor in which the steamand liquid are thoroughly mixed.

This invention relates to high temperature short time treatment ofliquids and, more particularly, to an improved steam infuser forsubjecting a heat sensitive liquid to high temperature short timetreatment.

High temperature short time treatment of liquids is a step frequentlyused in connection with the processing of heat sensitive liquids such asmilk. One process in which high temperature short time treatment of skimmilk is utilized is disclosed in U.S. Letters Patent No. 3,361,567 andassigned to the assignee of the present invention. High temperatureshort time treatment of liquids may also be used in other processes, forexample, to sterilize a liquid for canning.

One technique for accomplishing high temperature short time treatment ofheat sensitive liquids is to utilize apparatus which infuses steam intothe liquid, holding the mixture of steam and liquid for a short time,and then separating the steam from the liquid. The steam heats theliquid quickly and the liquid is cooled quickly when the steam isremoved. Apparatus for infusing steam into the liquid is known as asteam infuser. It is incumbent that the steam infuser uniformlydistribute steam in the heat sensitive liquid, otherwise, some portionsof the liquid may become overheated while others are not heatedsufiiciently. Naturally, it is also desirable that the steam infuser beof simple sturdy construction and be easily cleaned.

.It is an object of this invention to provide an improved steam infuserfor subjecting a heat sensitive liquid to high temperature short timetreatment.

Another object of the invention is to provide a steam infuser whichachieves a uniform distribution of steam in a heat sensitive liquid foruniform heating thereof.

Still another object of the invention is to provide a steam infuserwhich is simple and sturdy of construction and which is readilydisassembled and cleaned.

Other objects and the various advantages of the invention will becomeapparent to those skilled in the art from the following descriptiontaken in connection with the accompanying drawings wherein:

FIGURE 1 is a partially schematic, partially elevational and partiallysectioned view of a system for processing a heat sensitive liquid andwherein a steam infuser in accordance with the invention is utilized;

FIGURE 2 is an end view of the injector nozzle of the steam infuser ofFIGURE 1 taken along the line 2-2 therein; and

FIGURE 3 is an elevational view of a portion of the steam infuser ofFIGURE 1, rotated 90 degrees from the position shown in FIGURE 1.

The steam infuser of the invention includes an injector nozzle 11 forproviding a pressurized supply of heat sensi- 3,450,022 Patented June17, 1969 tive liquid and steam. A fluid conductor 41 is coupled to thenozzle and has an elongated fluid conducting passage therein throughwhich steam and heat sensitive liquid from the nozzle flow. The passageis formed in a substantially zigzag pattern to have a plurality of turnstherein. This creates turbulance in the iiuids passing through thepassage to effect thorough and uniform mixing of steam in the heatsensitive liquid.

In accordance with the invention, the fluid conductor may comprise acenter portion having a plurality of substantially straight elongatedparallel rst holes therein, and a plurality of substantially straightelongated parallel second holes therein. The second holes extendtransversely of the 4first holes and intersect the first holes atopposite outside surfaces of the center portion to form a plurality ofopenings along such opposite surfaces of the center portion. A pair ofplates, each secured to a respective opposite surface of the centerportion, are provided t0 cover the openings in the opposite surfaces ofthe center portion and to cooperate with the iirst and second holes toform the zigzag passage for steam and heat sensitive liquid.

In order to more particularly associate the invention with a practicalprocess in which it may be utilized, the process disclosed in U.S.Letters Patent No. 3,361,567, previously cited, will be summarized.Although the invention may be utilized in this process, it is to beunderstood that the invention is not limited to use in this process buthas application to many processes associated with heat sensitiveliquids.

The process disclosed in U.S. Letters Patent No. 3,361,567 is forrecovering milk protein from milk. The milk fat is first removed fromthe milk to provide a skim milk. The skim milk is then subjected to apreliminary heat treatment. The solids of the skim milk are thenincreased to between 10 and 35 percent solids and the resultant liquidis subjected to a high temperature short time treatment. In thisconnection, the skim milk is heated to at least 280 F. for l5 secondsand preferably, to 285 to 295 F. for 2O seconds. Of course, equivalenttime and temperature conditions may be utilized for the high temperatureshort time treatment.

The heat treated skim milk is then reduced in temperature to about 215F. and is acidiiied by the addition of an acid under turbulentconditions so as to assure uniform distribution of the acid in the skimmilk. The skim milk, after acid addition, forms into curd and whey withthe whey protein co-precipitating with the casein to provide ahandleable curd. The curd and whey are then separated and the curd maybe continuously roll pressed on a conveyor and simultaneously andsubsequently washed. The curd may then be ground in the presence ofadded water to very small particle size and the resultant dispersion ofmilk protein particles is centrifuged from the aqueous phase. The milkprotein is then ready for drying or further processing.

The steam infus'er of the invention may be utilized to perform the stepof high temperature short time treatment of the skim milk in the processjust described. The steam infuser of the invention includes a nozzle 11comprising a substantially cylindrical housing 12 defining a chamber 13.An ori-lice 15 opens into the chamber 13 tangentially of the wallsthereof and is the interior terminus of a liquid feed injection tube 17.

A second orifice 21 opens into chamber 13 tangentially of the Wallsthereof and represents the inner terminus of a tube 23. Tube 23, whichextends from the housing 12 of nozzle 11, is provided with suitableconnecting means 25 for connecting the tube 23 with a source of steam,not shown.

The one end of chamber 13 is Plug 31 may be removed for cleaning nozzle11. The other end of nozzle 11 is provided with an axial opening 35 inwhich a conical pipe 37 is threadably secured.

Pipe 37 conducts the fluid mixture of steam and skim milk into a fluidconductor 41. Conductor 41 has a center portion 42 in which are drilleda plurality of elongated substantially straight mutually parallel holes43. A further plurality of substantially straight elongated mutuallyparallel holes 44 are bored in center portion `42. and extendtransversely of holes 43. The center lines of holes 43 intersect thecenter lines of holes 44, respectively, at points lying in the planes ofopposite surfaces of the center section 42.. As a result, a plurality ofopenings 47 and 48 are left on opposite sur-faces, respectively, of thecenter portion 42.

A pair of plates 51 and 52 are secured by bolts 53 over the respectivesets of holes 47 and 48, respectively, and against the center portion42. Sealing Teflon gaskets 55 and 56 are sandwiched between the platesand the center portion 42. When secured over the openings 47 and 48,plates 51 and 52, together with the walls of the holes 43 and 44, form azigzag liuid conducting passage which has a plurality of substantialturns therein. This creates considerable turbulence in the liuid mixtureof steam and heat sensitive liquid passing through the fluid passage toeffect a thorough and uniform mixing of the steam in the heat sensitiveliquid.

Fluid leaving the fluid conductor 41 is conducted through a holding tube61 which comprises a straight tube of a length sufficient to hold themixture of steam and liquid for a desired period of time. A throttlevalve or back pressure valve 63 is provided at the far terminus ofholding tube 41 for maintaining a desired pressure in the holding tube,in the fluid conductor 41, in the pipe 37, and in the chamber 13 ofnozzle 11. A thermocouple 33 may be provided in tube 41 just prior tovalve 63 for indicating the mixture temperature. The mixture of steamand liquid leaving throttle valve 63 may then be injected into a fiashchamber 65 for separating the steam from the liquid. Separated steam isremoved through conduit 67 while the heat treated liquid may then beremoved and be processed in any desired way. For example, the liquid maybe canned as shown at 71 since it will have been sterilized by the hightemperature short time treatment. Alternatively, the liquid may be platecooled as at 73, or may be processed in some other way as represented by75.

In operation, steam is injected into the chamber 13 of nozzle 11 throughpipe 23 while liquid is injected into chamber 13 of nozzle 11 throughpipe 17. The tangential placement of the orifices and 21 causes thesteam and liquid to swirl about in chamber 13 under pressure. Thispressure causes a flow of the steam and liquid mixture into the fiuidconductor 41 wherein the considerable turbulence produced by the zigzagcourse fluid conducting passage therein thoroughly mixes and diffusesthe steam in the liquid in a uniform distribution. Although the legs ofthe fluid conducting passage in fiuid conductor 41 are coplanar, it isnot necessary that such be the case. The zigzag course which the passagefollows may extend in a three dimensional fashion as well as only twodimensions as shown.

As previously mentioned, it is incumbent that the steam infuseruniformly distribute the steam in the heat sensitive liquid to preventoverheating of some portions of the liquid while other portions areheated insufiiciently. By utilizing the construction of the invention,as shown and described, it has been found that sufiicient uniformity inthe infusing of steam into the liquid occurs such that substantiallysuperior results are attained over methods previously attempted.

In order to clean the steam infuser, the various threaded parts may bedisengaged to separate the nozzle 11 from the pipe 37 and the fluidconductor 41. Fluid conductor 41 may then be disassembled by removingbolts 53 and 54 and separating plates 51 and 52 from the center portion42. Ready access may then be had to holes 43 and 44 and a straight brushor similar cleaning device may be inserted in the holes through theopenings 47 and 48. Thus simple and effective cleaning of the device maybe effected. All that need be accomplished in reassembling the device isthat the plates 51 and 52 be repositioned, the bolts tightened, and thenozzle 11 and pipe 37 screwed back in place.

It may therefore be seen that the invention provides an improved steaminfuser for subjecting a heat sensitive liquid to high temperature shorttime treatment. The steam infuser achieves a uniform distribution of thesteam in the heat sensitive liquid for uniform heating thereof, and issimple and sturdy of construction and readily disassembled and cleaned.

I claim:

1. A steam infuser for subjecting a heat sensitive liquid to hightemperature short time treatment, said steam infuser including incombination, an injector nozzle comprising a housing defining asubstantially cylindrical chamber, a first orifice in said housingopening tangentially into said chamber for injecting heat sensitiveliquid therein, a second orifice in said housing opening tangentiallyinto said chamber for injecting steam therein, a third orifice in saidhousing opening axially into said chamber at one end thereof forconducting heat sensitive liquid and steam from said chamber, and meanscoupled to said nozzle for thoroughly mixing the heat sensitive liquidand steam to achieve a uniform distribution of steam in the heatsensitive liquid for uniform heating thereof, said mixing meanscomprising a fluid conductor having a center portion with a plurality ofsubstantially straight elongated mutually parallel first holes therein,said center portion having a plurality of substantially straightelongated mutually parallel second holes therein extending transverselyof said first holes, said first and second holes intersecting each otherat opposite surfaces of said center portion to form a plurality ofopenings along such opposite surfaces, and a pair of plates, eachsecured to a respective one of such opposite surfaces of said centerportion and covering said 45 openings therein to form said first andsecond holes into a zigzag passage for creating turbulence in the fluidspassing therethrough.

2. The combination of claim 1 wherein said plates are secured bymanually removable securing means to permit said plates to be removedfor straight through cleaning of said holes.

3. The combination of claim 1 wherein said first and second holes aredrilled and wherein the center lines of said first holes intersect thecenter lines of respective ones of said second holes in the planes ofsuch opposite surfaces of said center portion.

References Cited UNITED STATES PATENTS WALTER A. SCHEEL, PrmaiyExaminer.

J. M. NEARY, Assistant Examiner.

U.S. Cl. X.R.

